Gas phase thermal unit

ABSTRACT

A gas phase thermal unit, which includes an elongated vertically extending tubular housing having an interior cavity, a lower portion and an upper portion. A plurality of radial burner head conduits are positioned within the interior cavity in a lower portion of the housing, each of the conduits having a plurality of orifices, the orifices being oriented to create a vortex of gas movement. An ignition system is used to ignite gas emitted from the orifices to form high intensity flames. There is also a primary source of forced air having a radial air supply conduit associated with each burner head conduit, where each radial air supply conduit is adapted to create a vortex of air movement while delivering combustion air to a root of the flames of one of the burner head conduits, and a secondary source of forced air having associated air supply outlets adapted to create a vortex of air movement while delivering air to a tip of the flames to minimize oxide formation.

FIELD OF THE INVENTION

The present invention relates to a thermal unit, which consumes gasphase fuel.

BACKGROUND OF THE INVENTION

In the oil and gas industry, there are applications in which gas ventedfrom a gas well must be disposed of properly before releasing to theatmosphere. A number of thermal units have been developed for thispurpose and are variously described in the prior art as “gas flares” or“gas incinerators”. However, as the oil and gas drilling industrybecomes more environmentally responsible in regards to air pollution, asystem with higher combustion efficiency is required to meet current andfuture stringent air quality guidelines.

SUMMARY OF THE INVENTION

According to the present invention there is provided a gas phase thermalunit, which includes an elongated vertically extending tubular housinghaving an interior cavity, a lower portion and an upper portion. Aplurality of radial burner head conduits are positioned within theinterior cavity in a lower portion of the housing, each of the conduitshaving a plurality of orifices, the orifices being oriented to create avortex of gas movement. An Ignition System is used to ignite gas emittedfrom the orifices to form high intensity flames. There is also a primarysource of forced air having a radial air supply conduit associated witheach burner head conduit, where each radial air supply conduit isadapted to create a vortex of air movement while delivering combustionair to the root of the flames of one of the burner head conduits, and asecondary source of forced air having associated air supply outletsadapted to create a vortex of air movement while delivering air to a tipof the flames to minimize oxide formation. With the high vortex movementcreated around the burner inside the vertically elongated extendingtubular housing, clean combustion with high efficiency and flamesuppression can both be achieved by re-circulating heat and activechemical species to the base of the flame.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features of the invention will become more apparent fromthe following description in which reference is made to the appendeddrawings, the drawings are for the purpose of illustration only and arenot intended to in any way limit the scope of the invention to theparticular embodiment or embodiments shown, wherein:

FIG. 1 is a side elevation view, in section, of a gas phase thermal unitconstructed in accordance with the teachings of the present invention.

FIG. 2 is a top plan view, in section, of the gas phase thermal unitillustrated in FIG. 1, showing burner head conduit and primary airsupply conduit detail.

FIG. 3 is a detailed top plan view of one of the burner head conduitsand primary air supply conduits illustrated in FIG. 2.

FIG. 4 is a detailed transverse sectional view of the burner headconduit and primary air supply conduit illustrated in FIG. 3.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The preferred embodiment, a gas phase thermal unit generally identifiedby reference numeral 10, will now be described with reference to FIG. 1through 4.

Structure and Relationship of Parts:

Referring now to FIG. 1, there is shown gas phase thermal unit 10,including an elongated vertically extending tubular housing 12 having aninterior cavity 14, a lower portion 16, an upper portion 18, a top 15and a bottom 17. Housing 12 may be insulated with thermal insulation 20,such as ceramic fibre insulation. Upper portion 18 of housing 12 is of alength adapted to conceal any visible flame. Low pressure gas fromportable tanks regularly associated with drilling and well testingprocedures are vented through a low pressure vent line 22, which extendsfrom the exterior of thermal unit 10 to lower portion 16 of housing 12.Referring to FIG. 2, a plurality of radial burner head conduits 24 arepositioned within interior cavity 14 in lower portion 16 of housing 12.Referring to FIG. 3, each conduit 24 has a plurality of orifices 26 thatare oriented to create a vortex of gas movement. Referring again to FIG.1, an Ignition System 28, with a continuous pilot system, is used toignite gas emitted from orifices 26 to form high intensity flames. Thereis a primary source of forced air 30, and a secondary source of forcedair 36. Referring to FIG. 2, primary source 30 has a radial air supplyconduit 32 associated with each burner head conduit 24. Each radial airsupply conduit 32 is adapted to create a vortex of air movement whiledelivering combustion air to the root of the flames of one of the burnerhead conduits 24. Secondary source of forced air 36 has associated airsupply outlets 38 that are adapted to create a vortex of air movementwhile delivering air to the tip of the flames to minimize oxideformation. Referring to FIG. 1 a gas inlet 40 extends from below up to amanifold 42 depicted in FIG. 4 and is used to supply gas to radialburner head conduits 24. It is likely that liquids will be carried inthe gas to be burned. Therefore, referring again to FIG. 1, a liquidseparation chamber 44 is included that underlies manifold 42. Liquidseparation chamber 44 is adapted to contain liquids carried in the gassuch that liquids are separated by means of centripetal force into thebase of the liquid separation chamber 44.

Referring to FIG. 1, sub-floor 19, insulated or non-insulated, acts as aheat shield against high heat radiation from the burner to thecontrols/instruments and operators. Without this protective heat shield,direct radiant heat energy from the burner can potentially cause damageto the equipment and injuries to the operators.

Referring to FIG. 1, to stabilize gas phase thermal unit 10 in theupright, operational position, bottom 17 of housing 12 is mounted on askid 46 and laydown skid 48. Skid 46 is of a sufficient weight tosupport housing 46 in a free standing vertical orientation. For example,skid 46 may be filled with concrete. In addition, a laydown skid 48 thatextends along housing 12 is provided for transportation purposes.

With a burner design that creates high vortex movement, this system canachieve combustion efficiency as high as 99.9999% depending on the wellgas composition and flow rate. Also, with the properly staged air burnerconfiguration and a vertically elongated extending tubular housing, theflame can be fully concealed reducing ground level heat radiation andemitting light source which can cause discomfort to local residents.

Operation:

The use and operation of gas phase thermal unit 10 will now be describedwith reference to FIGS. 1 through 4. First, tubular housing 12 having aninterior cavity 14, a lower portion 16, an upper portion 18, a top 15and a bottom 17 is erected on skid 46. Low pressure gas from portabletanks regularly associated with drilling and well testing procedures arevented through a low pressure vent line 22, which extends from theexterior of thermal unit 10 to lower portion 16 of housing 12. Gas to beflared passes through gas inlet 40, through the liquid separationchamber 44, to manifold 42, and then to a plurality of radial burnerhead conduits 24 that are positioned within interior cavity 14 in lowerportion 16 of housing 12. Referring to FIG. 2, each conduit 24 has aplurality of orifices 26 that are oriented to create a vortex of gasmovement. The gas is ignited using an Ignition System 28, with acontinuous pilot system. The gas is mixed with air at the bottom of theflame to improve combustion using air from primary source of forced air30 through radial air supply conduit 32, and at the top of the flame tominimize oxidation formation using air from secondary source of forcedair 36 through supply outlets 38. Referring to FIG. 2, primary source 30has a radial air supply conduit 32 associated with each burner headconduit 24. Referring to FIG. 1, liquids that are carried in the gas tobe burned are separated by means of centripetal force into the base ofthe liquid separation chamber 44 that underlies manifold 42.

In this patent document, the word “comprising” is used in itsnon-limiting sense to mean that items following the word are included,but items not specifically mentioned are not excluded. A reference to anelement by the indefinite article “a” does not exclude the possibilitythat more than one of the element is present, unless the context clearlyrequires that there be one and only one of the elements.

It will be apparent to one skilled in the art that modifications may bemade to the illustrated embodiment without departing from the spirit andscope of the invention as hereinafter defined in the Claims.

1. A gas phase thermal unit, comprising: an elongated verticallyextending tubular housing having an interior cavity, a lower portion andan upper portion; a plurality of radial burner head conduits positionedwithin the interior cavity in the lower portion of the housing, each ofthe conduits having a plurality of orifices, the orifices being orientedto create a vortex of gas movement; an ignition system to ignite gasemitted from the orifices to form high intensity flames; a primarysource of forced air having a radial air supply conduit associated witheach burner head conduit, each radial air supply conduit being adaptedto create a vortex of air movement while delivering combustion air to aroot of the flames of one of the burner head conduits; and a secondarysource of forced air having associated air supply outlets adapted tocreate a vortex of air movement while delivering air to a tip of theflames to minimize oxide formation.
 2. The gas phase thermal unit asdefined in claim 1, further comprising a sub-floor, insulated ornon-insulated, to shield direct radiant heat energy from the burner tothe controls/instruments and operators which can potentially causedamage to the equipment and injuries to the operators.
 3. The gas phasethermal unit as defined in claim 1, wherein the housing is insulatedwith thermal insulation.
 4. The gas phase thermal unit as defined inclaim 3, wherein the insulation is ceramic fibre insulation.
 5. The gasphase thermal unit as defined in claim 1, wherein the housing has a topand a bottom, the bottom being mounted on a skid, the skid being ofsufficient weight to support the housing in a free standing verticalorientation.
 6. The gas phase thermal unit as defined in claim 1,wherein the upper portion of the housing being of a length adapted toconceal any visible flame.
 7. The gas phase thermal unit as defined inclaim 1, wherein a laydown skid is provided for purpose of transport,the laydown skid extending along the housing.
 8. The gas phase thermalunit as defined in claim 1, wherein a gas inlet extends from below up toa manifold which supplies gas to the radial burner head conduits.
 9. Thegas phase thermal unit as defined in claim 8, wherein a liquidseparation chamber underlies the manifold, the liquid separation chamberbeing adapted to contain liquids carried in the gas, the liquidsseparated by means of centripetal force into the base of the liquidseparation chamber.
 10. The gas phrase thermal unit as defined in claim1, wherein a low pressure vent line extends from the exterior of thethermal unit to the lower portion of the housing for venting lowpressure gas collected from portable tanks regularly associated withdrilling and well testing procedures.